Older mercury 850 (85hp) throttle question

skynyrdcat

Petty Officer 2nd Class
Joined
Mar 11, 2007
Messages
157
A friend asked me to take a look at his mercury. I can't find any legible numbers, but it appears to be a mid to late 70's 85hp (thunderbolt ignition).

He said he replaced the throttle cable and don't have much power now.

I've only done a visual so far, but the throttle cable only opens the butterflies about 1/2 way (actually a little less than half).

Is this cable adjustable? I see the threads on it, but if I adjust by those, then the throttle changes ends (carbs stay half open and won't close fully).

Is their a cam or something inside the control box that would make the throttle open more but still fully close?

I can get pics if needed, but don't want to start turning bolts until I get some feedback from those with more experience.

Thanks in advance!!!!
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,074
Re: Older mercury 850 (85hp) throttle question

The MerControls are not adjustable. The obvious question is whether the throttle and shift cables are switched at the motor. When you move the throttle handle, the first cable to move is the shift cable. The shift cable will then stop moving and the throttle cable will start to move.

also, shift to reverse and see if the shift cable moves backwards, at the motor.
 

skynyrdcat

Petty Officer 2nd Class
Joined
Mar 11, 2007
Messages
157
Re: Older mercury 850 (85hp) throttle question

The MerControls are not adjustable. The obvious question is whether the throttle and shift cables are switched at the motor. When you move the throttle handle, the first cable to move is the shift cable. The shift cable will then stop moving and the throttle cable will start to move.

also, shift to reverse and see if the shift cable moves backwards, at the motor.

Good points Chris, I'll take a look (may be a couple of hours before I can post results)!
 

skynyrdcat

Petty Officer 2nd Class
Joined
Mar 11, 2007
Messages
157
Re: Older mercury 850 (85hp) throttle question

Had a look this evening, and the cables were correct.

I did adjust the throttle cable (by setting it with the throttle wide open as oppsoed to closed) and the problem was fixed!
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,074
Re: Older mercury 850 (85hp) throttle question

Good, The MerControls usually have plenty of travel in the throttle arm.
 
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